Method and apparatus for analyzing hydrocarbon streams

Abstract

The present invention is a method and apparatus for identifying a mixture of particles using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). The particles are first reacted in a charge exchange reaction within the FT-ICR MS chamber using ionic partners that are chosen to discriminate among components of the mixture based on ionization potential. Mass spectra of test runs using different ionic partners may then be compared to identify components based on information gathered about both molecular mass and ionization potential.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to the field of mass spectrometry, and more particularly, to a method and apparatus for using charge exchange reactions in conjunction with mass spectrometry for analyzing and quantifying multiple compounds of similar molecular weight contained in a mixture. BACKGROUND OF THE INVENTION [0002] Mass spectrometry is a powerful analytical tool used in the identification of unknown compounds and elements. The technique measures the mass-to-charge ratio (m / z) of individual ionized molecules. Because the charge of those ions is usually known (and is usually plus or minus z, the charge of one electron), the mass of the ion may be deduced, and the molecule may be generally identified. [0003] A functional block diagram of a modern mass spectrometer 100 is shown in FIG. 1. An inlet 110 provides a location for introduction of a sample. The inlet may be configured to accept a solid, a liquid or a gas. The inlet is equipped to ...

AI Technical Summary

Benefits of technology

[0034] The apparatus may further comprise a vacuum pump connected to the chamber. In that case, the executable instructions further include the step of controlling the vacuum pump to introduce the sample mixture into the chamber at a pressure less than 10−6 torr. The executable instructions may alternatively or additionally include the step of controlling the vacuum pump such that the orbiting molecules are detected at a pressure less than 10−9 torr.

Problems solved by technology

While the EI process is simple, it can result in the decomposition of the molecules to be tested.

It is then necessary to indirectly deduce the original composition of the sample, often with ambiguous results.

Because the basic principles used in mass spectroscopy separate ions based on their mass-to-charge ratio, the technique is inherently limited in cases where the sample mixture contains compounds having similar atomic masses.

The use of those techniques, however, it often extremely time consuming.

For that reason, those techniques cannot be used on-line for real-time process control.

Furthermore, those techniques, when coupled to mass spectrometry, often do not yield reliable quantification of the mixture components.

That limitation also makes chromatography only marginally useful in on-line applications.

To the inventor's knowledge, there is currently no such technique available.

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